ACTIVITY 7.2.1: Confidence intervals for population proportions. Critical values for quick reference during this activity Confidence level Critical value 0.90 z- 1.645 0.95 Z = 1.960 0.99 Z' = 2.576 388018.2547466.qx32gy7 Jump to level 1 In a poll of 1000 randomly selected voters in a local election, 279 voters were 2 in favor of fire department bond measures 3 What is the sample proportion p? Ex: 0 123# What is the margin of error m for the 95% confidence level? Ex: 0 123